1. Field of the Invention
The present invention relates to an image data generating device, an image data generating method, and a computer-readable storage medium.
2. Description of the Related Art
In order to accurately convert paper-based media to electronic data, technology is being investigated that uses a machine-readable barcode to print a document while maintaining the security of information such as personal information or information related to the filename or another identifier (for example, see Unexamined Japanese Patent Application KOKAI Publication No. 2004-17538, pg. 1). In Unexamined Japanese Patent Application KOKAI Publication No. 2004-17538, personal information is barcode-converted into a personal information barcode, and logo barcode information is then generated by combining this barcode with logo data. The logo barcode information is then merged with print data to generate logo print data, which is then printed. When converting this printed document having barcode printed thereon to electronic data, the machine-readable filename or other identifier is obtained during scanning. In doing so, association with incorrect information is avoided.
At the same time, there exists a technology that generates both color image data and monochrome image data from the same subject document (for example, see Unexamined Japanese Patent Application KOKAI Publication No. 2005-39666, pg. 1, and Unexamined Japanese Patent Application KOKAI Publication No. 10-340273, FIG. 1).
In the invention disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2005-39666, a controller determines from a pixel tolerance level whether data is a monochrome image or a color image. In the case of a monochrome image, the data is converted into a monochrome file (1 bit per pixel). In the case of a color image, the data is converted into a grayscale file (8 bits per pixel). Since data is saved in a 1-bit or 8-bit format depending on whether the data is a monochrome image or a color image, less space is required to save image files.
In the technology disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 10-340273, a location to be displayed is identified by a monochrome map obtained from a monochrome image scanner. Additionally, a map for display including this location is generated by combining the monochrome map with a color map obtained from a color image scanner. The combined map is then displayed on a CRT.
In Unexamined Japanese Patent Application KOKAI Publication No. 2005-39666 and Unexamined Japanese Patent Application KOKAI Publication No. H10-340273 described above, data for one color image or one monochrome image is generated during a single scan. Thus, it was necessary to scan twice in order to obtain both monochrome image data and color image data.
However, there is a method to obtain both a color image and a monochrome image from a single scan. In this case, first color image data is generated, and then a monochrome image is generated from the generated color image data. However, the color image data is generated using a non-reversible (lossy) compression processing, such as JPEG. Thus, the monochrome image generated from the color image data has indistinct edges compared to the case wherein an image is scanned to generate monochrome image data. Consequently, when conducting information recognition processing using a monochrome image displayed from color image data, the recognition ratio was low, and obtaining correct information was difficult.